Morphological Study of Dispersion Phases in Heterogeneous Waste Form Materials for Efficient Nuclear Waste Containment
The efficiency of high-level nuclear waste immobilization by incorporating a host phase within a hollandite material structure can be increased by carefully synthesizing the dispersion phases inside the hollandite matrix. Also, estimation of the leaching rate from these nuclear waste forms is critical. Hence, conformal finite elemental model has been developed to study the effect of morphology of dispersive phases on diffusive nuclear flux. COMSOL Multi-physics is used as a computational tool to solve a Nernst-Plank Equation to study the diffusion leakage flux. A 2D model is built to identify the effect of volume fractions, surface areas, and different shapes of dispersion phase on the exit flux behavior. The results have indicated that there exists an optimum combination of different parameters such as volume fraction, surface area, position with respect to open boundary, and shape of dispersion phases for immobilization.
KeywordsDiffusion COMSOL Nernst-Planck Nuclear waste form
The authors are grateful for the support of Nuclear Energy University Program of the US Department of Energy (Award ID: DENE0008260), and the support for the present study by the Institute for Predictive Performance Methodologies at the University of Texas Arlington Research Institute (UTARI).
- 1.Aubin V et al (2004) The stability under irradiation of hollandite ceramics, specific radioactive cesium-host wasteforms. No. INIS-FR–3008. LCAES (UMR CNRS 7574)Google Scholar
- 2.Vittorio L et al (2004) Cesium release from ceramic waste form materials in simulated canister corrosion product containing solutions. No. INIS-FR–2898. Materials and engineering sciencesGoogle Scholar
- 3.Xu Y et al (2016) A-site compositional effects in Ga-doped hollandite materials of the form BaxCsyGa2x+yTi8−2x−yO16: implications for Cs immobilization in crystalline ceramic waste forms. Scientific reports 6:27412Google Scholar
- 4.Amoroso J et al (2014) Melt processed single phase hollandite waste forms for nuclear waste immobilization: Ba1.0 Cs0.3 A2.3 Ti5.7 O16; A=Cr, Fe, Al. J Alloy Compd 584:590–599Google Scholar
- 7.Lutze W, Ewing RC (1988) Radioactive waste forms for the futureGoogle Scholar
- 10.Sato H, Yui M, Yoshikawa H (Sept 2017) Ionic diffusion coefficients of Cs, Pb, Sm, Ni, SeO 4 and TcO 4 in free water determined from conductivity measurements SeOz- and TcO, in free water determined from conductivity measurements, 3131. https://doi.org/10.1080/18811248.1996.9732037
- 11.Sims DJ, Andrews WS, Creber KAM (2008) Diffusion coefficients for uranium, cesium and strontium in unsaturated prairie soil 277(1):143–147. https://doi.org/10.1007/s10967-008-0722-7